Into week 3 of the Fast BSD and going well thankfully. I am knocking on a bit now – coming up to 78, and about once a month I walk with a friend covering around 12 miles at a steady pace. My question is should I still try and cope on that day with 800 cals or should I increase my intake that day to compensate for the extra calories burned?
I’d be grateful for any views.

No, there’s really need. If your body needs more fuel it has your fat stores to utilise. Have you read Jason Fung’s The Obesity Code yet? Or just watch his videos on YouTube.
The way he describes it is imagine the body as a power station; you obviously have stores of fuel waiting to be processed but get regular deliveries. The stores are your fat and the delivery is the next meal. Your body has become accustomed to operating on the regular deliveries for power, but this WOE is reprogramming the body to go to the stores instead. So flick that switch and bingo! Fat burning!
Does that make sense?

Thanks for that Maggie. I’ll take a look at the video on YouTube you mentioned and maybe get the book.

Hi Actomox and MaggieBath! I would also just advise that you pay attention to the signals your body is giving you and respond flexibly as needed — I personally would find it hard to walk twelve miles and not add in a bit more protein or fat (but especially protein for muscle building — high quality like wild fish or grass fed beef) — if you find yourself extra tired or cranky (bad humor is my body’s signal for needing more food) or low energy then add in more. It doesn’t have to be a lot and it won’t wreck your progress.

Thanks for that Californiagirl. For me the sentence is complete at I would find it hard to walk 12 miles!

Ha ha MaggieBath! Twelve miles is a LONG walk!

Thanks to both of you – I’ll pack an extra couple of hard-boiled eggs, which will up the protein if needed without adding too many calories.
I might add that the 12 miles are usually on fairly level ground – any significant hills cause me too much hip discomfort these days!